An electrical switch for controlling an electric appliance disclosed in document DE 10 2007 014 174 A1 is in widespread use and has proven successful in practice. This switch has an external interface. A microprocessor disposed in the switch housing can be controlled through this external interface, and switching states or displays in the switch or the electrical appliance can be changed.
In addition, a battery-operated electronic clock is disclosed in U.S. Pat. No. 4,316,276. A single push-button switch is provided on the clock housing, which switch can be operated by the user while adhering to a specific code whereby a signal sequence can be initiated. A desired time display is then selected by repeat actuation of the switch. In addition, a reset function is described. At least two counters for the counting operation are provided in the switch. For use of this switch in an electronic appliance an additional switch is required as an ON and OFF switch of the appliance.